For mobile satellite communication, transmit/receive antennas may be used that have a low constructional height, on the one hand, and have a directivity pattern that can guarantee maximum reception quality of the signals irrespective of the position of a mobile subscriber relative to the satellite, on the other hand. For example, if the satellite signal arrives from a direction of fixed elevation, the antenna should guarantee constant reception quality irrespective of the azimuth angle, which is achieved, for example, with a conical directivity pattern for the antenna.
In this context, please refer to the following scientific publications:    [1] A. Popugaev and R. Wansch, “Low profile automotive antennas for digital broadcasting”, in 9th Workshop Digital Broadcasting, Erlangen, Sep. 18-19, 2008    [2] D. Sievenpiper, H.-P. Hsu, J. Schaffner, and G. Tangonan, “Antenna system for communicating simultaneously with a satellite and a terrestrial system”, U.S. Pat. No. 6,545,647, Apr. 8, 2003.    [3] D. Sievenpiper, “Forward and backward leaky-wave radiation with large effective aperture from an electronically tunable textured surface”, IEEE Transactions on Antennas and Propagation, vol. 53, no. 1, pp. 236-247, January 2005.    [4] L. Goldstone and A. Oliner, “Leaky-wave antennas I: Rectangular waveguides”, IRE Transactions on Antennas and Propagation, vol. 7, no. 4, pp. 307-319, 1959.    [5] A. A. Oliner and D. R. Jackson, “Leaky-wave antennas”, in Antenna Engineering Handbook, 4th ed. McGraw-Hill, 2007, ch. 11.    [6] M. Schühler, R. Wansch, and M. A. Hein, “Experimental study of the radiation characteristics of a finite periodic structure excited by a dipole”, in Proc. Of EuCAP'2009, Berlin, Germany, Mar. 23-27 2009, pp. 3055-3059.
Propagation of leaky waves along periodic structures has been a well-known phenomenon for quite some time, just like the attempt at utilizing them for antenna applications. Leaky wave arrangements, or leaky waveguides, are understood to mean waveguides for electromagnetic waves that allow energy to enter and exit not only at the ends, but to a certain degree also across the entire length or surface area of the leaky wave arrangement (of the leaky waveguide).
However, conventional leaky-wave antennas have apertures, i.e. radiation areas whose lateral sizes are large, at least in one dimension, as compared to the wavelength λ0 at the working frequency f0. Typical implementations of leaky-wave antennas in accordance with conventional technology thus comprise lateral dimensions in the order of magnitude of, e.g., 20 wavelengths (20λ0), wherein at a working frequency f0 of 2.2 GHz, a wavelength λ0 corresponds to about 13.6 cm, and, thus, the following is true for the dimensions: 20*λ0=2.73 cm.